Silica-templated ordered mesoporous carbon thin films as electrodes for micro-capacitors

A binderless continuous thin film of a mesoporous carbon material was directly synthesized on a graphite current collector using an ordered mesoporous silica thin film as a hard-template. The nanostructure of the silica, the composite silica/carbon and the mesoporous carbon thin films was characterized by field emission scanning electron microscopy coupled to energy dispersive X-ray spectroscopy, transmission electron microscopy and Raman spectroscopy. The silica thin film, which was uniformly deposited onto the graphite plate surface, presented mesopores of around 8 nm perpendicularly disposed to the current collector. The carbon thin film, which almost replicates the nanostructure of the silica thin film, showed mesopores of around 2-3 nm. Electrochemical characterization of both the mesoporous carbon and the composite silica/carbon thin films, by cyclic voltammetry and galvanostatic charge-discharge in a 1 M H2SO4 solution, demonstrated that the synthesized thin films showed exceptional properties in terms of specific capacitance, rate performance and electrochemical stability to be used as electrodes for micro-capacitors.